Metering pump



Nov. 20, 1934- A. KORFMACHER METERING PUMP Filed May 13, .1932

2 Sheets-Sheet 1 Fig. 3

In venzop:

Patented Nov. 20, 1934 UNITED STATES METERING PUMP Anton Korfmacher, Cologne-Lindenthal,

Germany Application May 13, 1932, Serial No. 611,194 In Germany November 14, 1930 12 Claims. (Cl. 221-102) Known oil pumps are normally equipped with a spring loaded suction and pressure valve and are therefore not adapted to be calibrated.

The present invention relates to a pump for drawing of! and metering oil, syrup-like liquids I and the like having a pump piston sliding in the metering vessel in which on the suction stroke the liquid rises above an overflow edge whereupon the piston returning on the pressure stroke displaces the superfluous liquid. into the overflow, then closesthe overflow while the outlet for the delivery of the liquid is first opened after the piston has closed the overflow. A stand pipe is provided-in the pump cylinder which pipe serves as overflow and passes into the bellshaped piston so that the overflow edge is freed on the suction stroke of thepiston but is covered during the pressure stroke. Preferably the overflow also serves as inlet.

Certain embodiments of the invention are shown by way of example in the accompanying drawings in the cases of a single cylinder and a double cylinder construction.

In the drawings Figs. 1, 3 and 4 show various vertical sections through a single cylinder pump.

Fig. 2- shows a corresponding cross section.

Fig. 5 shows a vertical section through a twin pump.

Figs. 6 and '7 show two different sections on a somewhat larger scale through the corresponding outlet cock.

Fig. 8 shows a further embodiment.

At its lower end the metering cylinder 1 is closed by a base 2 through which projects a pipe 35 3 which constitutes the extension of the suction conduit 4. By means of the tube 3 an annular metering space 5 is formed within the cylinder 1 and this metering chamber can contain a quite definite quantity of liquid for example one quarter of ,a litre, one half a. litre or one litre, up to the overflow edge 6 of the stand pipe 3. It follows directly that the capacity of the metering chamber 5 can be altered by displacing the overflow edge 6 for example by screwing the.

the associated piston rod 9 but the rod projects into the sleeve 10 which is secured to the central portion of the piston. At the head of the piston rod 9 is a transverse bolt 11 which passes through slots 12. in the sleeve 10. Thus the piston 7 can be moved relatively to the associated piston rod 9 by an amount equal to the length of the slots 12. However disposed beneath the transverse bolts 11 of the piston rod within the sleeve 10 is a spring 13 which normally urges the piston into 5 a definite end position relatively to the piston rod 9. The upper closure cover 14 of the metering cylinder 1 is also bell-shaped and carries a counting mechanism 15.

The piston rod 9 is actuated by the hand crank 7 17 by way of the pinion 18, the piston rod 9 being provided at its lower end with a toothing 16. At the same time however the stop device for the outlet aperture 19 in the bottom 2 of the metering chamber 1 is actuated by the piston rod 9. A stop cock 20 may for example serve as closure device and its axial extension 21 may be constructed as outlet connection. The stop cock carries two ratchet wheels 22, 23 side by side. Correspondingly two pawls 24, 25 preferably spring mounted are provided on the piston rod 9 and are laterally offset .(Fig. 2) so that for example the segment 24 engages in the ratchet wheel 22 only on the downward motion of the piston rod and thereby rotates the cock 20 into the open position whereas in the motion of the piston rod 9 in the opposite direction the segment 24 resiliently yields. On the other hand'the pawl 25 engages in the ratchet wheel only during the upward motion of the piston rod in order to rotate the cock 20 into the closed position whereas in the downward'motion of the piston it does not engage in the teeth ofthe ratchet wheel 23 but yields resiliently.

Briefly the mode of operation of the arrangement is as follows: I

In Fig. 1 of the drawings the parts are shown in the position they assume at the end of the suction stroke. The metering chamber 5 is filled with liquid to far above the edge 6 of the stand pipe 3. 1 If now the hand crank 17 is rotated in clockwise direction then the piston '7 initially remains in its highest position because the outlet 19 of the metering chamber is temporarily still closed and it is not possible to force back the excess liquid which has been drawn in through the suction pipe 4 because the foot valve 26 prevents return flow. Thus the transverse bolt 11 of the piston rod compresses the spring 13 in the sleeve 10 to a certain extent. Thus the pressure in the cylin-' der space and in'this suction conduit naturally increases. Under this pressure the valve seating 28 operated on by the spring 27 in the foot valve 26 yields until the valve member 29 encounters the stop 30 which projects into the aperture 01' the valve seating 28 and terminates shortly below the valve body 29. The valve body 29 is thus raised from the corresponding valve seating 28 so that liquid can flow back through the suction pipe 4 into the supply reservoir whereby a certain release of pressure is attained. If desired the stop 30 could be omitted and instead apertures 58 be provided in the lateral wall of the foot valve 26 which apertures would be exposed on the downward depression of the valve seating 28 so that the liquid could flow back. When the piston has approximately reached the upper edge 6 ,of the stand pipe 3 it is precisely centered by the crownshaped projections 31 with interrupted outer edge provided on the vertical tube so that the sharp closure edge 32 of the piston does not encounter the sharp overflow edge 6 of the stand pipe 3. When, as shown in Fig. 3, the cut off edge 32 reaches the overflow edge 6 then a very definite quantity of liquid is trapped in the metering chamber 5, which liquid on the further movement of the piston can at first escape in no direction because the outlet aperture 19 is still closed. The

piston rod 9 will thus be displaced relatively to the piston 7 with further tensioning or the spring 13 in the sleeve 10. During this phase of motion of the piston rod independently or the piston, the pawl 24 comes into engagement with the corresponding ratchet wheel 22 and thereby rotates the cock 20 in such way that, as shown in Fig. 4, the inlet aperture 33 of the cock is brought into coincidence with the outlet aperture 19 of the metering space 5 so that the liquid can flow out. If desired the pawl 24 can be arranged at such a level that it has already rotated the cock 20 into a position immediately preceding the open position when the piston reaches the position shown in Fig. 3 in whichit closes the metering space at the top. The crank 17 then needs only to be rotated through a small further angle in order to effect the opening of the outlet 19. The tension on the spring 13 is then immediately released and on further rotation of the hand crank the piston '7 finally arrives in the lowermost end position shown in Fig. 4 in which it has displaced the last residue 01 the metered quantity of liquid from the metering chamber 5. It now the hand crank is rotated in the opposite direction the piston rod 9 initially moves independently or the piston in the upward direction until the transverse bolt 11 has attained the uppermost end position in the slot 12 of the sleeve 10 as shown in Fig. 1. During this displacement of the piston rod relatively to the piston the cock 20 is again rotated into the closed position by means of the pawl 25 which durin the downward motion did not operate the cock but resiliently yielded. Thus during the upward motionof the piston a vacuum occurs in the metering chamber 5 so that liquid is drawn into the suction conduit 4 and the stand pipe 3 simultaneously. When the piston passes the over flow edge 6 of the vertical pipe 3 then the liquid passes directly irom the stand pipe 3 into the metering chamber 5. During this phase of motion or the piston rod 9 the pawl 24yields resiliently away from the corresponding ratchet wheel 22 so that the cock remains temporarily in the closed position. Then the cycle of operations commences again from the position shown in Fig. 1.

In order to prevent the liquid from dripping from the outlet aperture of the outlet connection 21 after the metering chamber hasbeen emptied, the cap 34 is provided which embraces the outlet pipe 21 and is provided on its underside only with an outlet aperture 35. As shown in Figures 2 to 4 the outlet 36 coincides with the aperture 35 of the cap 34in theopen position only of the cook 20 so that it is only in this position that the liquid can flow out. If on the other hand the cock is in the closed position then the aperture 36 is turned to one side and covered by the cap The mode of operation of the twin pump shown in Fig. 5 corresponds precisely to that of the single cylinder pump already described. A common outlet is provided for the two metering cylinders A and B and is closed by a stop cook 43 constructedin the formof a multi-way tap. The outlet conduits 40 and 41 of the metering chambers A and B discharge as shown in Fig. 7 into the housing 42 of the cock 43. in relatively oifset positions in the longitudinal direction of the cock 43. The cock 43 is provided with two correspondingly disposed outlet passages 44 and 45 so that the outlet of one metering chamber is always closed when the other is open. Correspondingly the outlet pipe 21 is also provided with two such offset outlet apertures 48, 49 so that on emptying the metering cylinder A or the metering cylinder B one 01 the apertures coincides with the outlet aperture 35 of thecap 34.

In the construction of the stop cock arrangement of Figs. 6 and 7, not only is the outlet Irom the metering chambers controlled by the cook 43 but the inlet into the chambers also. Grooves 46 and 47 are cut into thesurface of the cock and in that position of the cock in which the liquid is forced out from the one metering chamber connect the other metering chamber by way of the base aperture with the space 48! which is connected to the suction conduit 4. In this way no alteration is made in the accuracyof the measurement because, as described above, .on reversing the direction of rotation of the hand crank the cock is at first rotated so that in any case at the beginning of the pressure stroke 01' a cylin-.

der the suction conduit at the base of the metering chamber A or B is first closed and then the metering chamber is closed at its upper end in the manner described by the co-operation of the inner edge of the piston 7 and 'the upper edge of the stand pipe 3. It is only then that the outlet is opened. Obviously with a single cylinder pump also the liquid which is to be measured can be drawn in wholly or in part through a corresponding channel in the cock. This is of particular importance in the case of large pumps in which the high vacuum otherwise occurring in the mev tering chamber 5 would render the actuation extremely diflicult.

Instead of the arrangement described, the suction conduit 4 may if desired be connected to the metering cylinder 50 at the top as shown on a much reduced scale in Fig. 8. On the suction stroke the bell-shaped piston 53 exposes the inlet aperture 54 with the upper edge 52 of its projecting central portion, whereupon the liquid immediately flows from the suction chamber 56 connected with the suction conduit 54 into the metering cylinder 50. The excess quantity of liquid drawn in over the quantity to be measured is displaced through the aperture 54 on the pressure stroke until the edge 52 of the piston traps a quite definite quantity of liquid in the space 51. Then on the further actuation of the piston, for

example in the manner described above, theoutlet to the pressure conduit 5'! is opened. The outaround which the said extension telescopes when the piston operates to force liquid from the cylinder.

2. A metering pump consistingo! a cylinder,

a bell-shaped piston sliding therein, a, suction tube extending upwardly into the cylinder, said suctioh tube being in liquid-tight contact with the bell portion of the piston during a portion of the pressure stroke of the piston whereby a constantly uniform quantity of liquid is trapped in the cylinder and expelled when the stroke of the piston is continued to empty the cylinder.

. 3. A metering pump as per claim 1,, in which the cylinder is provided with a stop cock having two toothed segments, a piston rod, two pawls arranged on the piston rod, the teeth of one pawl being operative oppositely to the teeth of the other pawl for engaging the segments of the stop cock during the stroke of the piston rod in a1- ternate succession whereby the said stop cock is operated.

4. A metering pump as per claim 1, in which the cylinder has an outlet controlled by a stop cock, means for opening and closing the stop cock during the operation of the piston, and an outlet pipe in which the stop cock is rotatable for controlling the outlet opening thereof.

5. A metering pump as per claim 1, in which an outlet pipe is provided in association with a pump housing, the said outlet pipe having a lateral opening, a stop cock rotatable in said outlet pipe and having an outlet opening, the outlet opening of the stop cock and outlet pipe registering when the piston is operated toexpel liquid from the cylinder.

6. A metering pump consisting of two cylinders, a piston sliding in each of the cylinders, tube-like extensions on the said pistons at their upper ends, a suction intake pipe for each of the cylinders closed by the tube-like extensions of the pistons when the pump is in operation, an outlet for the two metering cylinders, and means for successively controlling the flow of fluid from the cylinders for discharging liquid therefrom.

7. A two-cylinder metering pump as per-claim 6, in which the common means for controlling the outlets of the two cylinders is provided with special channels operative for sucking in the liquid through the bottom of the metering chamher.

8. A metering pump consisting of two cylinders, a piston sliding in each of the cylinders, tube-like extensions on said pistons closed at their upper ends, a suction intake pipe for each of the cylinders closed by the tube-like extensions of the pistons when the pistons operate to expel liquid from the cylinders, an inlet from a source of supply to the suction intake pipes, a conduit for the two meteringcylinders, and .a valve operative to control the passage of liquid from the storage tank to thesuction pipes and release excess liquid in the suction pipes for return to the source of supply. I

9. A metering pump comprising a metering vessel having inlet and outlet openings, means for closing the outlet opening, a reciprocating piston 'sliding in the metering vessel, means associated controlling the outlet opening, a reciprocating piston slidable in the metering vessel, a tubular extension on said piston operative to open and close the inlet opening, the relation of the parts being such that the inlet opening is closed by the said extension during the pressure stroke of the piston, the liquid remaining in the metering vessel after the inlet opening is closed being forced therefrom, and means for unguarding the outlet opening during the pressure stroke of the piston after the inlet opening is closed.

11. -A metering pump comprising a cylindrical metering vessel and a reciprocating piston therein, the, said metering vessel having an inlet through which on the suction stroke liquid is delivered to the metering vessel in excess of the quantity to be measured, the relation of parts being such that on the liquid expelling stroke of the piston the excess of liquid is forced back in the inlet, means associated with the piston for closing the end of the inlet when said excess liquid has been expelled, the said metering vessel having a liquid discharge opening with means for opening and closing the same, the said opening means being actuated after the inlet has been closed as aforesaid.

12. A metering pump comprising a cylinder having a guarded discharge opening, a tube in the cylinder, said tube having a suction opening through which fluid is delivered to the cylinder, 9. piston sliding in the said cylinder, a tubular extension of the diameter of the tube having the suction opening the space between the tube and the wall of the cylinder constituting a metering chamber, said tubular extension cooperating with the tube for closing the suction opening during the movement of the piston when engaged in forcing fluid from the metering chamber through the discharge opening.

ANTON KORFMACHER.

" Vessel having inlet and outlet openings, means for 

